New murid (Mammalia, Rodentia) fossils from a late Pliocene (2.4 Ma) locality, Hadar A.L. 894, Afar Region, Ethiopia

ABSTRACT

This paper describes a new assemblage of fossil murids (Mammalia: Rodentia) from an Oldowan archeological site, Hadar, A.L. 894. The dates for the site are well constrained to between 2.35 and 2.9 Ma and the site itself has an estimated age of 2.4 Ma. The A.L. 894 assemblage is the first described from the younger Busidima Formation at Hadar and extends the time range for micromammals at Hadar by 800 ka. The assemblage of 28 specimens has eight taxa represented, a surprising diversity given the sample size. The specimens include a fossil skull of Thallomys, a poorly documented African endemic rodent, as well as one of the earliest occurrences of a small gerbilid, such as Gerbillus in East Africa. Fossil rodents from this time period are important for the interpretation of hominid paleoecology as well as understanding the processes underlying the evolution of ecological communities through shallow, deep-time.

ACKNOWLEDGMENTS

Field work at Hadar was conducted under the Hadar Research Project directed by W. Kimbel and D. Johanson on behalf of the Institute for Human Origins, Arizona State University, and E. Hovers from the Hebrew University of Jerusalem, with funding from the U.S. National Science Foundation, the National Geographic Society, and the Institute for Human Origins. I thank the Authority for Research and Conservation of Cultural Heritage, of the Ethiopian Ministry of Youth, Sport and Culture, along with the Education and Tourism Bureau of the Afar Regional State for granting permission to conduct the field work and for help with logistics and planning. I also thank the National Museum of Ethiopia for permission to conduct laboratory work in Addis Ababa. Thanks to L. Gordon and H. Kafka (NMNH, Washington, D.C.) for their capable assistance in working with museum collections. Special thanks go to E. Hovers for conducting the archeological excavations and fossil collection at A.L. 894 and for reading early drafts of the manuscript. Additional thanks to M. Skinner at the Max Planck Institute for collecting the microCT scans and producing the rendered image of specimen A.L. 894-365. The manuscript was greatly improved by helpful comments from Christine Denys and one other, anonymous, reviewer.

Handling editor: Robert Asher